The concept of mechanical means for driving rotative tools, such as drilling, tapping or screw driving means, is an old one and many, possibly thousands, of such means have been offered to the trade over a period of many years. These devices have been both hand and power driven and many of them have included both speed and directional control.
However, insofar as I am aware, the majority of these devices have been designed primarily for workshop or machine shop use and few, if any, of them are appropriate for surgical use. It is self-evident that mechanisms intended for surgical use must meet a wide variety of criteria that are not necessary for use in other environments and it is therefore equally self-evident that mechanisms devised for general use are not usually acceptable for surgical use. Among such criteria are driving by nonelectric means, providing a tool small enough to be light in weight, easy to handle and of minimum obstruction to the vision of the operator, full sealing against escape of lubricant and total enclosure of all working parts excepting only the tool engaging means and the direction selecting means.
Accordingly, the objects of the invention include:
1. To provide means for rotating a tool in either rotative direction in order to perform a drilling or tapping operation or to drive or remove screw means, for example.
2. To provide means, as aforesaid, wherein such rotative direction is maintained regardless of the direction of axial pressure upon the tool.
3. To provide means, as aforesaid, wherein the direction of rotation may be quickly and easily selected, capable of operation at a moment's notice by surgical personnel and further wherein such selection may be accomplished by the operator by feel rather than under the necessity of visual observation.
4. To provide a tool, as aforesaid, wherein the motor may be housed in the handle thereof whereby to minimize the diameter of the portion of the housing containing the driving mechanism, whereby to minimize the obstruction to vision presented over the operating area to the user of the tool.
5. To provide a rotary tool, as aforesaid, wherein all operating components are fully enclosed excepting only the part actually engaging the rotating tool and a manually operable part for selecting the direction of rotation of the tool.
6. To provide a device, as aforesaid, wherein all lubricated parts are effectively sealed against escape of lubricant.
Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspection of the accompanying drawings.